1. Field of the Invention
The invention relates to a building elevator with an elevator mast and an elevator car and with at least one electric drive motor for the elevator car, for moving the same along the elevator mast, an overload-prevention means being provided.
2. Description of Related Art including information disclosed under 37 CFR 1.97
Building elevators of this type are known in principle. Such building elevators are used for transporting passengers or materials, the design of the elevator car differing in dependence on the carrying purpose. In particular in the case of building elevators for transporting passengers, an overload-prevention means is provided, i.e. it has to be ensured that the elevator is deactivated if the load which is to be transported exceeds a predetermined maximum value.
In the case of building elevators with an electric geared motor as the drive motor, it is known to allow the torque arm of said geared motor to act on a limit switch. With corresponding deflection of the torque arm of the geared motor as a result of overload, the overload-prevention means is then automatically actuated by the limit switch being triggered. This solution is suitable for building elevators with one electric motor as the drive. However, should a building elevator which can transport greater loads be equipped with two such drive motors, such an overload-prevention means is not suitable.
The object of the invention is to provide an overload-prevention means in the simplest manner possible for a building elevator with at least two drive motors.